By Nyta Mann BBC News Online political correspondent

He didn't expect to feel quite so jaunty this early but with a year still to go before the contest, the Liberal Democrat home affairs spokesman is relishing the battle to become London's mayor.

"Yes, I've surprised myself really," he confesses. "It wasn't like I'd ended up in a siding with nothing interesting to do. I was doing a job I'd asked for, thoroughly enjoying it, very busy."

But then someone crunched the numbers for a Hughes London mayoral candidacy. It became clear that in the expected three-horse race (Tory Steve Norris and incumbent Ken Livingstone being the other two), he had a strong chance of winning thanks to the voting system used.

He made clear to Lib Dem HQ he wasn't interested in running unless in anything but a seriously funded campaign rather than the comparative two-bob affair of last time round - "I told them I'm not going to do it knocking on my bank manager's door".

They agreed. Having won his party's nomination, a �1m-plus campaign is planned - the biggest Lib Dem spend aside from the general election, and a long way from the party's chicken feed �50,000 bid in 1999.

"We will fight this election as if it's a national by-election."

A party at ease with itself

The move, if successful, will to some degree take him away from the national scene - but he doesn't mind. He believes the long forecast battle for the Lib Dem soul, over whether the party should trim further to the right, is no longer the threat it once was.

"I guess because we've got quite a lot of young Turks, which is a good thing, they are impatient to move more quickly and make more progress," says Mr Hughes. He means the likes of Mark Oaten and others who have more keenly pushed the takeover-Tory-territory line.

"The last two elections have brought in a lot of bright people in their thirties who don't want to be in opposition for the rest of their careers, and they're pushing very hard to make sure we're ambitious about the seats we can win."

But the ideological bloodletting many had expected has been safely avoided.

"The tension that we were going to be veering off in a right-wing direction came to a peak leading up to the public services debate at our party conference last autumn," he concedes, but in the end the Lib Dem grassroots "realised it wasn't quite as frightening as they feared".

As a result, his party is "quite comfortable" now.

Cross-party backers

Mr Hughes insists that well-known backers of both the Labour and Conservative parties have approached him promising financial and other support for his mayoral bid, though he refuses to name names yet - "it's far too early for that".

The next stage on his path to City Hall is a consultation process in which, ahead of the autumn, he is sounding out people across the capital ahead of coming up with the key proposals by which he hopes to distinguish himself from his main rivals.

"That campaign process is going to find the three most significant areas of disagreement with each of them, so people will know just what they will get if they vote for me."

He also promises there will be at least one central, flagship policy to match the congestion charging proposal of Mr Livingstone's first mayoral manifesto.

Mr Hughes knows a solid programme is required, rather than relying on a platform simply of Livingstone-is-a-letdown.

"Ken hasn't been a disastrous mayor and he hasn't been a crap mayor," he says. Instead, he has been a "risky and uninspiring" one.

Uninspiring for having failed, congestion charging aside, to grasp the opportunities the role of mayor affords, according to Mr Hughes.

And risky along the lines of Mr Livingstone's comments about US President George Bush being a corrupt venal coward whose downfall he looked forward to as much as to that of Saddam Hussein - made on the eve of a promotional drive to woo more American tourists to London.

Liberating

The mayor's remarks were undoubtedly clumsily timed. But wouldn't it be fair to say that it is the fact of Mr Livingstone having uttered them that Mr Hughes most objected to, while perhaps not actually disagreeing with their substance?

"I don't go quite as far as that," he says. "I just don't think you get anywhere with gratuitous insults. So there is a difference - I would not have said those sorts of things."

Having run Charles Kennedy a close second for the Lib Dem party leadership, Mr Hughes was perfectly placed to take the deputy's job recently up for grabs. He was torn over whether to go for it but doesn't regret opting for the mayoral nomination instead.

"I think I would have got it, and it would have been fine," he says of the number two's job. "But deputy leaders are more constrained, you have to literally make sure that at all stages you follow the agenda which is collectively set and somebody else leads.